The innate modesty of one of the world's most charismatic and endangered creatures may prove its undoing.

Conservationists say the giant panda is being badly hit by poaching in the Chinese bamboo forests where it lives.

Its wild population has remained stable for several decades.

But attempts to breed pandas in captivity are meeting with little success, because the animals are largely uninterested.

The global environment network WWF says in a report that pandas remain "on the brink".

Lack of money

The report, Giant Pandas in the Wild, says the animals have reached a critical point in attempts to save them.

There are thought to be about 1,000 pandas in the wild, living in several provinces of western China.

Few cubs are born in captivity

But Stuart Chapman of WWF-UK, who worked for two years in a panda reserve, said the statistic was misleading.

He said: "Although it appears the panda population has remained stable over the last 20 years, this figure masks the harsh reality that panda reserves are chronically under-funded. The future of these most loved symbols of conservation cannot be left to chance.

"The species is extremely vulnerable to illegal logging and poaching. The Chinese Government must urgently create forest corridors to link isolated panda populations and provide more funds for existing reserves, or the panda will remain on the brink of extinction."

A survey in one county in Sichuan in 1999 showed a 30% decrease in panda habitat since 1987.

One of the report's co-authors, Dr Lu Zhi, said: "Habitat fragmentation is especially dangerous for pandas, as they must adjust to the life-cycles of bamboos, which flower and die periodically.

"Small isolated panda populations, whose diet consists almost entirely of various bamboo species found in high mountain areas, face a risk of inbreeding.

"This could lead to reduced resistance to disease, less adaptability to environmental change, and a decrease in reproductive rates."

Celibate captives

As serious a threat as inbreeding is the pandas' marked lack of interest in breeding at all when anyone is watching.

For many years conservationists had believed that the animals were in fact more interested in eating and sleeping than in sex.

But the WWF report says that sex appears not to be a problem for pandas in the wild.

It notes: "The problem with giant pandas raised in captivity is that they are often not interested in mating with the member of the opposite sex chosen for them - or they seem unable or unwilling to breed."

Bamboo is the pandas' staple

Barely a quarter of adult pandas in captivity are breeding, and the few that do are not contributing to the survival of their wild relatives.

"No panda born in captivity has ever been released into the wild," said Stuart Chapman. "The reality is that more pandas are dying than are being born.

"The captive breeding programme is not making any contribution to wild populations. It is unsustainable."

Commitment needed

Not only are the wild pandas not increasing; they are actually declining, for two reasons.

Animals are still being captured in the forests and sent to breeding centres, despite the very limited prospects of success.

And WWF says there has been a "significant" increase in hunting by poachers in some parts of the pandas' range since 1998, when a logging ban came into force.

Privately, WWF says attempts to save the panda are simply not working, and are unlikely to do so unless the Chinese Government shows far more commitment than it has so far.